Black Men With Advanced Prostate Cancer Live Longer Thanks to New Hormone Therapies

Prostate cancer has historically been more common, more aggressive and more lethal in African-American men compared with other racial groups. But new findings presented at the 2019 Genitourinary Cancers Symposium reveal that Black men with advanced prostate cancer treated with newer hormone therapies lived 20 percent longer than their white counterparts, reports the American Society of Clinical Oncology (ASCO).

Megan McNamara, MD, lead study author and assistant professor of medicine at Duke University School of Medicine in Durham, North Carolina, and other researchers analyzed Veterans Health Administration data from April 2013 to March 2018. The data focused on men with prostate cancer whose only prior treatment was surgical castration or hormone therapy to lower testosterone levels (known as medical castration).

The analysis included 2,123 white and 787 Black men with metastatic castration-resistant prostate cancer (mCRPC), meaning it progresses despite testosterone-lowering therapy. These men were treated with either Zytiga (abiraterone acetate) or Xtandi (enzalutamide), which were approved in 2013 and 2014, respectively, for use in men with mCRPC who didn’t receive chemotherapy. Zytiga interferes with an enzyme needed to produce male hormones while Xtandi blocks signals from receptors that trigger hormone production.

African-American men who were treated with either of the new hormone therapies lived for an average of 30 months in comparison with 26 months for white men. This was a significant difference in overall survival, meaning it was probably not attributable to chance.

“These findings reinforce what is already the standard of care, but it’s important to have real-world studies,” McNamara said during a media briefing ahead of the conference. “We need to make sure every African American who’s eligible for these medicines gets them.”

Scientists are looking to find out why Black men live longer than white men when treated with certain medicines for prostate cancer as well as why these men have a higher incidence of prostate cancer.

To that end, they’re investigating whether key gene variations involved in androgen metabolism and transport may help explain racial differences in treatment response. The goal, McNamara says, is to tailor treatments more effectively and find biomarkers that can help guide the development of targeted therapies.

“These findings provide important evidence that African-American men with metastatic prostate cancer, who have long had among the highest incidence and poorest outcomes of this disease, may now have better survival when treated with newer prostate cancer medications as compared with other men,” said ASCO expert Robert Dreicer, MD.